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Plants have been used for centuries as therapeutic resources for various pathological conditions and are occasionally considered as the only resource available to some communities. However, knowledge on the potential of traditional medicinal plants have been lost over the years. Strategies that can guarantee the prospection of popular knowledge regarding medicinal plants to stimulate the spread of information between generations are therefore of enormous value. Thus, the present study aimed to investigate the use and knowledge on medicinal plants of students from a public school in Vila Velha (Brazil) and their associated community, including parents. In this urban locality, data were obtained by the application of a semi-structured questionnaire to 206 people from the school community. Although homegrown cultivation seems to be an uncommon practice in urban contexts, the use of medicinal plants by the sampled population was significant (80%), as well as the interviewees’ confidence on its therapeutic action (90%). It is worth mentioning that more than 70% of the respondents presented their parents and/or grandparents as their main source of information, highlighting the importance of popular knowledge valorization.

Mango wilt, caused by Ceratocystis fimbriata, is one of the most serious diseases affecting mango production worldwide. Considering the great variation in the basal level of wilt resistance among mango cultivars, this study aimed to assess changes in photosynthesis and the role played by the carbon metabolism on two mango cultivars with contrasting responses to C. fimbriata infection. Assessment of disease and plant physiology variables was performed over 21 days. The response of the mango cultivars against fungal infection was associated with an increase on the mobilization of starch from the leaf tissue around the infection sites on stems. Plants of cv. Uba were less susceptible to mango wilt and, presumably, better capable of mobilizing reserves for the production of defense compounds, which prevented colonization of the stem inner tissues and the consequent disruption of xylem hydraulic conductivity and leaf photosynthesis. On the other hand, the inability in mobilizing and targeting carbon for the production of defense-related compounds should have accounted for the higher susceptibility of cv. Palmer to C. fimbriata infection.

Mango wilt, caused by Ceratocystis fimbriata, is a disease of great economic importance in mango production. Considering that the physiological effects of this vascular disease are not fully characterized, this study aimed to investigate some alterations in mango leaves from cultivars Uba and Tommy Atkins, respectively, resistant and moderately resistant to mango wilt. The relationships between relative lesion indices (upward relative lesion length (URLL), the downward relative lesion length (DRLL) and the radial fungal colonization (RFC)) and water relations and gas exchange and chlorophyll a fluorescence parameters were evaluated at 10, 20 and 30 days after inoculation. The foliar concentrations of lipid peroxidation, total pigments and total free amino acids and proline were also determined. The URLL, DRLL and RFC increased overtime in both Uba and Tommy Atkins cultivars, but reached the greatest values for cv. Tommy Atkins. Although cultivars did not present contrasting results for most of the evaluated parameters, the relative changes between inoculated and non-inoculated plants of each cultivar were more disparate in plants from cv. Tommy Atkins. There were decreases of 55, 73, 65 and 22 %, respectively, for net carbon assimilation rate (A), stomatal conductance to water vapor (g s), transpiration rate (E) and internal-to-ambient CO2 concentration ratio (C i/C a) for inoculated plants from cv. Tommy Atkins in comparison to the non-inoculated plants. For inoculated plants from cv. Uba, there were decreases of 25, 41 and 36 % for A, g s and E while C i/C a decreased by 17 % in relation to the non-inoculated plants. Inoculated plants of cvs. Tommy Atkins and Uba showed pronounced reductions for midday leaf water potential and apparent hydraulic conductance relative to the control. Inoculated plants from cv. Uba showed values of predawn leaf water potential that were 25 % higher in comparison to inoculated plants from cv. Tommy Atkins. In addition, decreases in total chlorophyll concentration as well as increases in free amino acids and lipid peroxidation occurred for inoculated plants from cv. Tommy Atkins.

Brown spot (BS), caused by the fungus Bipolaris oryzae, is one of the most important diseases contracted by rice. We investigated the effect of magnesium (Mg) on the development of BS, caused by Bipolaris oryzae, and the effects of disease development on the photosynthetic performance of rice (Oryza sativa L.) plants (cv. Metica-1) grown in nutrient solutions containing 0.25 or 4.0 mM of Mg. Assessments of BS severity, leaf Mg and pigment concentrations (total chlorophylls and carotenoids), were carried out at 120 h after inoculation, in addition to gas exchange parameters,. Higher leaf concentration of Mg was observed in plants supplied with 4.0 mM Mg than in those supplied with 0.25 mM. The increase in leaf Mg was accompanied by a decrease in BS severity, higher concentration of total chlorophyll and better photosynthetic performance. Plants supplied with 4.0 mM Mg had higher average values for carbon assimilation, stomatal conductance and internal leaf CO2 concentration when compared with plants supplied with 0.25 mM Mg. Conversely, the concentration of carotenoids was lower in plants supplied with the higher Mg rate. These results suggest that Mg suppresses disease severity and preserves photosynthetic performance by allowing for better stomatal conductance and, consequently, greater availability of CO2 at the carboxylation sites.

Mango wilt, caused by the fungus Ceratocystis fimbriata, is an important disease affecting mango production. In view of the beneficial effects of potassium (K) in other profitable crops and the lack of information about the effect of macronutrients on mango wilt development, the present study aimed to evaluate how mango plants supplied with K respond physiologically when infected by C. fimbriata. Mango plants (» 3 years old) from cultivar Ubá were grown in plastic pots containing 58 mg of K·dm−3 (original K level based on the chemical analysis of the substrate) or in plastic pots with substrate amended with a solution of 0.5 M potassium chloride (KCl) to achieve the rate of 240 mg K·dm−3. Disease symptoms were more pronounced in inoculated plants grown at the lower K level. Substantial declines in stomatal conductance, in line with decreases in the internal-to-ambient CO2 concentration ratio and the absence of detectable changes in the chlorophyll a fluorescence parameters, suggest that the decrease in the net carbon assimilation rate is due, at least initially, to stomatal limitations. High concentrations of K and manganese were found in the stem tissues of inoculated plants and supplied with the highest K rate, most likely due to the involvement of these tissues in the local development of defense mechanisms. The results of this study suggest that the supply of K favored the physiological performance of mango plants and their resistance against C. fimbriata infection.

Mango wilt is one of the most important diseases affecting mango production, yet the physiological mechanisms underlying host responses to this fungal infection are poorly known. The disease attenuation displayed by some mango cultivars might be related to higher antioxidant capacities in leaves. To test this hypothesis, the activities of a range of enzymes (e.g. superoxide dismutase and catalase) and metabolites (e.g. ascorbate and glutathione) involved in the antioxidant system, as well as some markers for oxidative stress (e.g. hydrogen peroxide and malondialdehyde equivalents), were evaluated for 30 days after the inoculation of mango plants with Ceratocystis fimbriata. Tommy Atkins plants displayed higher values for the upward, downward and radial fungal colonization of the stem tissues than Uba plants. In contrast to the working hypothesis, Tommy Atkins plants exhibited more prominent increases in enzyme activities and metabolite concentrations related to oxidative stress responses. These increases were minimal, if any, in Uba plants. These results suggest that Tommy Atkins plants are less effective at restraining fungal spread through vascular tissues and thus trigger leaf antioxidant defences to cope with the developing stress.

Mango wilt, caused by Ceratocystis fimbriata, is one of the most important diseases affecting mango yields in Brazil. Information regarding the biochemical mechanisms involved in mango resistance against C. fimbriata is absent in the literature. Thus, the present study determined and quantified alkaloids and phenolics in the stem tissue of mango plants from Palmer (susceptible) and Ubá (resistant) cultivars. Furthermore, it was examined the effect of these secondary metabolites against C. fimbriata growth in vitro. The high-performance liquid chromatography revealed that the concentration of two alkaloids (theobromine and 7-methylxanthine) and six phenolic compounds (caffeic acid, p-coumaric acid, gallic acid, protocatechuic acid, catechin and epicatechin) in the inoculated plants from cv. Ubá was higher in comparison with inoculated plants from cv. Palmer. The concentration of the secondary metabolites was higher in the non-inoculated plants from cv. Palmer than in the inoculated ones, while the opposite was observed for plants of cv. Ubá. Peaks in the concentrations of secondary metabolites in the inoculated plants from both cultivars occurred at 7 and 14 days after inoculation. The different concentrations (10 to 30 mg∙mL−1) of secondary metabolites added to the Petri dishes greatly inhibited C. fimbriata growth over time. These results suggest that secondary metabolites played an important role in the resistance of mango plants against C. fimbriata infection.

Although mango is one of the tropical fruits of greater interest in the world trade, literature concerning their rootstocks (characteristics and utilization) is scarce. This study aimed to characterize mango plants from cv. Imbú, widely used as rootstock in the Zona da Mata region, State of Minas Gerais (MG), Brazil. Though fruits of this cultivar do not present desirable commercial characteristics, this study allowed us to characterize part of plant morphology and fill a gap in the literature, providing subsidies for future investigations. For such, 'Imbú' plants (˜ 4-years old) from the collection of the Universidade Federal de Viçosa, located in Viçosa -MG were evaluated. The descriptors were: (i) leaf blade division;(ii) leaf composition; (iii) petiole length in relation to leaf blade; (iv) phyllotaxis, (v) leaf position in relation to the branch insertion; (vi) leaf shape; (vii) leaf apex and base angles; (viii) leaf margin category; (ix) venation; (x) leaf length and thickness; (xi) leaf length/thickness ratio; (xii) leaf texture; (xiii) leaf fragrance; (xix) leaf color. The leaves were depicted as lanceolate, with entire margins and sharp angles at the base and apex of the leaf blade. The intensity of the green color of the leaf blade was considered intermediate and the abaxial surface staining showed less intense than that observed in the upper side. The fruits were processed and separated into peel, pulp and seeds in order to evaluate the flesh color, fresh weight and percentage of seeds, peel and pulp. It was determined the soluble solids content, starch concentration, the peel and the pulp color, the cerosity, the percentage evaluation of peel, pulp and seed and the pulp firmness. The average number of germinated seedlings per seed was estimated for 230 sown seeds. RESUMO Apesar de a manga ser uma das frutas tropicais de maior interesse no comércio mundial, a literatura sobre os seus porta-enxertos (características e utilização) é escassa. Este estudo teve como objetivo caracterizar as mangueiras da cv. Imbu, amplamente utilizada como porta-enxerto na região da Zona da Mata de Minas Gerais (MG), Brasil. E, embora frutos dessa cultivar não apresentem características comerciais desejáveis, este estudo permitiu caracterizar parte da morfologia da planta e preencher uma lacuna na literatura, fornecendo subsídios para futuras investigações. Para tal, folhas completamente expandidas da porção mediana de ramos expostos à luz solar e frutos plenamente desenvolvidos foram coletados de plantas da cv. 'Imbu' (˜ 4 anos de idade) da coleção da Universidade Federal de Viçosa, localizada no município de Viçosa - MG. Os descritores foram: (i) divisão lâmina de folha; (ii) a composição da folha; (iii) comprimento do pecíolo em relação à lâmina de folha; (iv) filotaxia, (v) a posição das folhas em relação à inserção do ramo; (vi) a forma de folha; (vii) ângulos do vértice da folha e de base; (viii) categoria margem da folha; (ix) venação; (x) comprimento da folha e espessura; (xi) Relação espessura / comprimento da folha; (xii) textura da folha; (xiii) fragrância da folha; (xix) cor da folha. As folhas foram descritas como lanceoladas, com margens inteiras e ângulos afilados na base e ápice da lâmina de folha. A intensidade da cor verde da lâmina foliar foi considerada intermediária e a coloração da superfície abaxial mostrou menos intensa do que a observada no lado superior. Os frutos foram processados e separados em casca, polpa e sementes, a fim de avaliar a cor da polpa, o peso fresco e percentagem de sementes, casca e polpa. Foi determinado o teor de sólidos solúveis, concentração de amido, coloração da casca e da polpa, a cerosidade, a percentagem de casca, de polpa e de semente e a firmeza da polpa. O número médio de plântulas germinadas por semente foi estimado para 230 sementes semeadas.

This study aimed to analyze the antioxidant system responses and photosynthetic performance of maize cultivars (ECVSCS155 and HIB 32R48H) infected by Stenocarpella macrospora. The activities of some antioxidant enzymes and metabolites and the concentration of reactive oxygen species in maize leaves as well as chlorophyll a fluorescence imaging parameters were assessed. For both cultivars, the enzymatic and non-enzymatic components of the antioxidant system were dramatically altered in the infected leaves. As the disease symptoms became more noticeable, enzyme activities (e.g., peroxidases and catalases) and the concentration of ascorbate and glutathione decreased accordingly. The concentrations of hydrogen peroxide and malondialdehyde equivalents increased, thereby contributing to the intensification of lipid peroxidation upon damage to cell membranes caused by fungal infection. Decreases in maximum fluorescence, maximum PSII quantum efficiency, effective PSII quantum yield and quantum yield of regulated energy dissipation coupled with increases in initial fluorescence and quantum yield of non-regulated energy dissipation were directly related to the progressive loss of photosynthetic activity coupled with the development of oxidative stress during the S. macrospora infection process.

This study was designed to characterize and describe host cell responses of stem tissue to mango wilt disease caused by the fungus Ceratocystis fimbriata in Brazil. Disease progress was followed, through time, in inoculated stems for two cultivars, ‘Ubá’ (field resistant) and ‘Haden’ (field susceptible). Stem sections from inoculated areas were examined using fluorescence light microscopy and transmission and scanning electron microscopy, coupled with energy-dispersive X-ray microanalysis. Tissues from Ubá colonized by C. fimbriata had stronger autofluorescence than those from Haden. The X-ray microanalysis revealed that the tissues of Ubá had higher levels of insoluble sulfur and calcium than those of Haden. Scanning electron microscopy revealed that fungal hyphae, chlamydospores (aleurioconidia), and perithecia-like structures of C. fimbriata were more abundant in Haden relative to Ubá. At the ultrastructural level, pathogen hyphae had grown into the degraded walls of parenchyma, fiber cells, and xylem vessels in the tissue of Haden. However, in Ubá, plant cell walls were rarely degraded and hyphae were often surrounded by dense, amorphous granular materials and hyphae appeared to have died. Taken together, the results of this study characterize the susceptible and resistant basal cell responses of mango stem tissue to infection by C. fimbriata.